ABSTRACT
This study has revealed the change of the soil micro-ecology of farmlands, which used for ginseng cultivation, brought by comprehensive soil improvement. The process of soil improvement was described as follows： soil was sterilized using trichloronitromethane, and then perilla seeds were planted. After growing up, the perillas were turned over into the field and fermented, then organic fertilizer was added. Rotary tillages were carried out during the intervals. Physical and chemical properties of treated soil were measured, as well as microbial diversity, which was illustrated using 16s high through-put sequencing. The survival rate and growth data of ginseng seedlings were recorded. The analysis showed that after improvement, the soil organic matter content was increased and soil bulk density was decreased, compare to the controls, and the fertility in 0-20 cm of soil layer was increased in the treatment. Additionally, the soil microbial diversity was changed greatly. In detail, alpha diversity of the soil decreased after soil improvement while the beta diversity increased. In order to verify the achievement of soil improvement, ginseng seedlings were planted. Compared to the untreated land blocks, the survival rate of ginseng on improved blocks was increased up to 21.4%, and the ginseng physiological index were all better than the controls. Results showed that comprehensive soil improvements including soil sterilization, green manure planting and organic fertilization application effectively improved the soil micro-ecology in farmlands. This study will pave the way for the future standardization of ginseng cultivation on farmlands.
ABSTRACT
Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles.
ABSTRACT
This study analysed the changes of the soil micro-ecology in the process of soil sterilization, green manure returning farmlands and fertilization. The methods of soil improvement was initially built which ensured the successful proceed of ginseng cultivation in farmlands. The soil chemical properties were analysed, the diversity and composition of bacterial community after soil sterilization, sterilization+green manure returning farmlands and sterilization+green manure returning farmlands+fertilization. The results exhibited that measures of soil improvement decreased the pH, increased soil fertility, declined the diversity of bacterial community and changed the composition of soil bacterial community. The comprehensive measures of sterilization+green manure returning farmlands+fertilization decreased the ginseng death rate compared to the control. Our data indicated that soil micro-ecological environment was changed by the treatments of soil sterilization, sterilization+green manure returning farmlands and sterilization+green manure returning farmlands+fertilization, and comprehensive measures improved the survival rate and guaranteed the development of ginseng cultivation in farmlands.